POI Strategies (core/poi_fun)

Internal subpackage implementing the different strategies for computing Points of Interest (POIs) from NIfTI segmentation volumes. End users typically call the high-level helpers in poi.py and vert_constants.py; the modules here provide the underlying algorithms.

Modules

Module	Description
ray_casting.py	Casts rays through a volume to find surface-intersection points
vertebra_direction.py	Derives superior/inferior/anterior/posterior unit vectors per vertebra
vertebra_pois_non_centroids.py	Computes non-centroid anatomical landmarks (process tips, endplates)
pixel_based_point_finder.py	Locates extreme/boundary pixels within a label for POI placement
strategies.py	Pluggable strategy objects for POI computation
save_load.py	JSON serialisation/deserialisation for POI objects
save_mkr.py	Export POIs as 3D Slicer markup files (.fcsv, .mrk.json)
poi_abstract.py	Abstract base classes shared across POI modules
poi_global.py	POI_Global — POI container in world-coordinate (mm) space
_help.py	Internal helpers (not part of the public API)

Key symbols

Symbol	Module	Description
POI_Global	poi_global.py	World-space POI container; used after POI.to_global()
save_poi	save_load.py	Serialise a POI to a JSON file
load_poi	save_load.py	Deserialise a POI from a JSON file
save_poi_as_slicer_markup	save_mkr.py	Write POIs as a 3D Slicer .mrk.json markup file

Coordinate system

POIs inside this package use the same convention as poi.py: - Local (is_global() == False): voxel indices (i, j, k) into the reference NIfTI - Global (is_global() == True): world coordinates in mm, consistent with the NIfTI affine